Peptide library refers to a combination of hundreds to thousands of peptides, a combination and sequence of which are arbitrarily varied using combinatorial chemistry. The peptide library is used for the development of a potential preliminary new medicine (a lead compound) having a biological activity.
PS-SPCL is a kind of peptide library. The PS-SPCL is a combination of mixtures that are prepared in a way of fixing one of 19 amino acids (except cysteine) in a specific position and connecting mixtures of the 19 amino acids in remaining positions. The PS-SPCL is used for the development of new peptide hormone materials, the definition of antibody epitopes, and the development of antimicrobial, antibiotics, enzyme detergent, and physiological active peptide.
FIG. 1 is a schematic diagram illustrating a scheme of PS-SPCL. As shown in FIG. 1, in mixtures of the first group of the PS-SPCL, different specific amino acids each are fixed in first positions and random amino acids are placed in remaining positions at the same rate. In mixtures of the second group, different specific amino acids each are fixed in second positions and random amino acids are positioned in remaining positions at the same rate. Also, in mixtures of the third group, different specific amino acids each are fixed in third positions and random amino acids are placed in remaining positions. In the above, a peptide synthesis process controls positioning specific amino acids in specific positions only and positioning random amino acids in remaining positions.
Thus, the PC-SPCL is composed of a plurality of peptide pools in which different specific amino acid is fixed in each sequence position.
For example, if pentamer PS-SPCL is made from 20 amino acids, 20 5=100 different peptide pools become one set.
The completed set is, as shown in FIG. 2, used to perform a screening process suitable to each purpose such as a reaction with specific materials or influence on enzyme. As a result, obtained is the result as to whether the most desired effect is obtained when any amino acids are positioned in first positions and also, whether it is most effective that any amino acids are positioned in second and third positions. In generalization, a linear peptide sequence that is a disclosure of an optimal amino acid by position is secured.
However, the PS-SPCL used in this process consumes a long time and many efforts and costs in its manufacturing because of its characteristic, but the PS-SPCL becomes extinct and cannot be used after once use.
Particularly, because the screening process is performed sequentially, it takes a few days to a few weeks to obtain a result though there is somewhat a difference depending on target materials.
As described above, the conventional art has a drawback in that it takes a long time and makes many efforts to search new materials using PS-SPCL and it continuously consumes the high-priced peptide library in view of the characteristic of the PS-SPCL.